Donald Olding Hebb FRS[1] (July 22, 1904 – August 20, 1985) was a Canadian psychologist who was influential in the area of neuropsychology, where he sought to understand how the function of neurons contributed to psychological processes such as learning.

[4] A Review of General Psychology survey, published in 2002, ranked Hebb as the 19th most cited psychologist of the 20th century.

He completed his master's degree in psychology at McGill in 1932 under the direction of the eminent psychologist Boris Babkin.

The focus of study at McGill was more in the direction of education and intelligence, and Hebb was now more interested in physiological psychology and was critical of the methodology of the experiments there.

He decided to leave Montreal and wrote to Robert Yerkes at Yale, where he was offered a position to study for a PhD.

At Harvard, he did his thesis research on the effects of early visual deprivation upon size and brightness perception in a rat.

That same year, on a tip from his sister Catherine (herself a PhD student with Babkin at McGill University), he applied to work with Wilder Penfield at the Montreal Neurological Institute.

From this, he deduced the prominent role that external stimulation played in the thought processes of adults.

Putting the Picture Anomaly Test to use, he provided the first indication that the right temporal lobe was involved in visual recognition.

In fact, in one adult patient, who had a large portion of his frontal lobes removed in order to treat his epilepsy, he noted "a striking post-operative improvement in personality and intellectual capacity."

From these sorts of results, he started to believe that the frontal lobes were instrumental in learning only early in life.

In order to test his theory of the changing role of the frontal lobes with age, he designed a variable path maze for rats with Kenneth Williams called the Hebb-Williams maze, a method for testing animal intelligence later used in countless studies.

This became one of the main principles of developmental psychology, later helping those arguing the importance of the proposed Head Start programs for preschool children in economically poor neighborhoods.

Afterward, he returned to McGill University to become a professor of psychology in 1947 and was made chairman of the department in 1948.

In 1966, Hebb married his third wife, Margaret Doreen Wright (née Williamson), a widow.

In 1977 Hebb retired to his birthplace in Nova Scotia, where he completed his last book, Essay on Mind.

He was appointed an honorary professor of psychology at his alma mater, Dalhousie, and regularly participated in colloquia there until his death at 81, in 1985.

The award is presented yearly to a person who has made a significant contribution to promoting the discipline of psychology as a science by conducting research, by teaching and leadership, or as a spokesperson.

A combination of his years of work in brain surgery mixed with his study of human behavior, it finally brought together the two realms of human perception that for a long time could not be connected properly, that is, it connected the biological function of the brain as an organ together with the higher function of the mind.

Hebb was instrumental in defining psychology as a biological science by identifying thought as the integrated activity of the brain.

His theory was that everything we experience in our environment fires a set of neurons called a cell assembly.

An enriched environment with varied opportunities for sensory and motor experiences contribute to children developing the cell assemblies and phase sequences necessary for continued learning in adulthood.

By raising them in an enriched environment, the rats showed improved maze learning in adulthood.

[22] This research into environmental enrichment contributed to the development of the Head Start Program used today.

The study demonstrated that children of lower socioeconomic status homes, with fewer economic resources, learn fewer words and acquire vocabulary more slowly than children of professional parents with a higher socioeconomic status with access to more varied and enriched vocabulary experiences.

[25] The Hebbian theory of learning implies that every experience a person encounters becomes set into the network of brain cells.

As a professor at McGill, he believed that one could not teach motivation, but rather create the conditions necessary for students under which to do their study and research.

Speaking at a Harvard symposium on sensory deprivation in June 1958, Hebb is quoted as remarking: The work that we have done at McGill University began, actually, with the problem of brainwashing.

The chief impetus, of course, was the dismay at the kind of "confessions" being produced at the Russian Communist trials.